Daniel Mortimer looks set to depart Cronulla for the English Super League just a day after playing a key hand in their last-gasp NRL win over Wests Tigers.

Journeyman Daniel Mortimer appears set to depart Cronulla just a day after helping the NRL premiers overcome the Wests Tigers.

Less than 24 hours after coming up with two big plays in Cronulla's 24-22 win over the Tigers at Southern Cross Group Stadium on Saturday, it was reported Mortimer was set to join English Super League club Leigh Centurions mid-season.

The Sharks were approached for comment, however, did not respond.

Cronulla coach Shane Flanagan sung Mortimer's praises after the 28-year-old was a standout in what was his debut in the black, white and blue.

The Tigers looked headed for victory before the former Parramatta, Sydney Roosters and Gold Coast utility imposed himself on the game.

Playing his first game in over a year, Mortimer came up with two key plays after coming on as a replacement hooker midway through the second half.

First he jumped out of dummy-half in the lead-up to Chad Townsend's four-pointer before putting in a deft drubber for Jayson Bukuya's 78th minute match-winner.

"He did his knee (in the first month of the season) and he was out for eight weeks and he's only just come back over the last few weeks," Flanagan said.

"I thought his experience and the way he brought players onto the ball out of dummy-half in that 30-minute stint was outstanding."

The Sharks were once again far from impressive, against the Tigers, but keep on keeping on.

Without State of Origin stars James Maloney, Andrew Fifita, Jack Bird, Valentine Holmes and Wade Graham, Cronulla were wasteful in possession and lost the penalty count 7-4.

However, they came up with the big plays when it counted to remain in touch with Melbourne, two wins behind the ladder leaders.

The Sharks have won both of their Origin-affected games - after scraping home against Canterbury in round 12.

"We knew if we could just get some back to back sets, get some consistency in our footy then we'd be able to score points," Sharks skipper Paul Gallen said.

"We did that in the last 10 minutes to a certain degree. They scored even though we were all over them.